Safety device for machinery.



R. B. BENJAMIN.

SAFETY DEVICE FOR MACHINERY.

APPLIOATION FILED 001'. 2a, 1911.

Patented Dec. 3, 1912.

3 SHEBTSSHEET l.

Fig 7 1/21 R. B. BENJAMIN.

SAFETY DEVICE FOR. MACHINERY. -APPLIOATION FILED OCT. 28, 1911.

1,046,373. Patented Dec. 3, 1912.

3 SHEETS-SHEET 2.

R. B. BENJAMIN.

SAFETY DEVICE FOR. MACHINERY.

PPPPPPPPPPPPPPPPPPPPPPPPPPP I REUBEN B. BENJAMIN, OF CHICAGO, ILLINOIS.

SAFETY DEVICE FOR MACHINERY.

Specification of Letters Patent.

Application filetliOctober 28, 1911. Serial No. 657,330.

T all whom it may concern:

Be it known that I, REUBEN B. BEN- ence being had to the accompanying draw-- 0 ing, forming a part of'this specification.

My invention relates to protective devices for stamping presses, die presses and the like. It is, in fact, applicable to any form of press .or machine which is adapted to be intermittently thrown into or out of oper ation.

One of the objects of my invention is to provide an improvement in safety or protective attachments of that class which require the use of both hands of the operator to effect the tripping of a stamping press or the like. Heretofore in safety attachments of this character, particularly those applicable to that class of punch presses adapted i to run open, ithas been possible for the operator to quickly move the controlling handles, levers or buttons, or the like, to initially start the tripping operation, and then remove one hand from the controlling or interlocking lever, button or handle, and

feed the die press with that hand. That is,

the safety devices have been so constructed that after they have once been set in motion they will not return to normal position upon 5 the release of the interlocking or controlling member, but will continue to be in a position to permit the operation of the tripping mechanism. Such a device, instead of af,- fording, the maximum protection to the I operator by insuring the use of both hands for tripping the machinery, tends to be a source of greater danger in that the operator, being able to set the device in motion and then return tot-he feedingof the press, i is tempted to'hurriedly'set, the safety devicesand then, without due caution, attempt to insert the material in the machine to be operated upon, such hurry and lack of caution tending rather to increase the danger than otherwise.

It is one of the objects of my invent-ion to provide an electrically controlled device which necessitates the use of both hands of the operator until the machinery is actually tripped. I have found that after the machinery has actual y tripped, the period between the actual tripping thereof and the descending of the die, in event it is a stamping press, is so'short that it would be practically impossible for an operator to get his hands in a dangerous position.

It is a further object of my invention to provide a device which will be very sensitive in its operation and which immediately upon the removal of either hand afterthe tripping mechanism has been set in motion, will permit the tripping mechanism to returnto normal position. i

Patented Dec. 3, 1912.

For the purpose of disclosing my invention I have illustrated one embodiment thereof applied as a safety attachment to a punch press having a reciprocating plunger.

In the drawings illustrating the embodiment of my invention and the application thereof'Figure 1 is a side elevation of a plunger press show-ing my safety attachment applied thereto Fig. 2 is a front elevation .of the punch press wit-h my attachment applied thereto; Fig. 3 is a detail sectional view showing the tripping mechanism of the punch press; Fig. 4 is an enlarged detail elevation of the connecting mechanism between the tripping lever and the tripping mechanism of the punch press; Fig. 5 is an end elevational detail View of the controlling magnet and the. manner of attachment thereof; Fig. 6 is a plan .view.

of the tripping lever connect-ion; Fig. 7 is a side elevation showing the trippinglever connection in non-operative position; and Fig. 8 1s a diagrammatic .connectlons.

view of the circuit Referring now to the press illustrated in I the drawings, this machine takes the form 4 of a stamping press of ordinary construction. This press has the usual framework carryinga table 2 over which operates the usual reciprocating punch-carrying member An .eccentric crank on;the driving shaft t serves -to reciprocate the punch carrying member for the purpose of pressing, out the material. The shaft 4 is driven from a pul ley wheel 5 which is loosely mounted on the shaft and adapted, to run free thereon except during the intervals it is connected to the shaft by the clutching mechanism. The clutching mechanism may be ofany desired construction and is illustrated as consisting of a rotatable key 6 mounted in a suitable slot in the shaft 4 and adapted when rotated to I engage in slots or openings 7 v formed in the hub of the pulley Interposed between an abutting stop; 8 carried on the collar of the shaft and the lower end of the arm 9, integrally formed with the key, is a coiled'sprin-g 10 which has a tendency to move the arm to a position to give the key 6 a half turn to throw the clutch into a connecting position. When the pulley is running free or when the press is in an untripped position the arm 9 is held against movement, under the influence of the spring 10, by a tripping stop 11 pivoted at 12 to the frame of the machine. This tripping stop is moved out of the path of the arm'9 to permit the clutch to trip by the movement' of'a tripping rod 14.

The lower end of the rod 14 is connected by a link mechanism with the operating lever 15, this link mechanism being so constructed that it is normally inoperative to transmit the movement imparted by the op.- erating lever 15 and is only rendered operative by the use of the second hand of the operator. The operating lever 15 is pivoted to-a stud or bolt 16 extending from" the frame of the machine and the connecting mechanism between this lever and the rod 14 i comprises a pair of links. One of the links,

17, is pivotally connected to the lever 15 at 18 and has its oppositeend free; the other link, 19, is provided with a slot 20 which fits over a pin 21 passing through an eye 22 formed in'thelower end of the rod 14 and is pivotally connected at 23 with the free end of the link 17. A coiledspring 24, having one end engaging the lever 15, is wrapped around the pivot point 18 ofthe link 17 and has its other end engaging the lower portion ofa right angle flange 25 on the link 17 to hold the link in the position illustrated in Fig. 4. y The eye 22 of the rod 14.fits between the bifurcated ends of a pivoted arm 26 and the pin-21 secured in the eye also extends through openings formed i in the bifurcated ends of the arm 26. The

opposite end'ofjthe arm 26 is pivoted on the bolt 16. The arm thus serves as a guide for the lower end of the rod 14. The centers of the pivots 18, 23 and 21 are such that when the lever 15 is. depressed the two links 17'and 19 will tend to 'separate,'as shown -'.jin Fig. 7, so that unless some means'is provided for holding the links together, when the'lever 15 is depressed no movement will be transmitted to the rod 14. The rod 14 is held in its raisedj osition or in the nontripping position and is moved to non-tripping position' when disconnected from the lever 17,. by the spring retracted rod 13 mounted on the side of the frame 1 and'con nected at its lower end to thepin 21. y

In order to connect the two'links together- I I provide a spool magnet-'27 which is secured by means of a flange 28 formed thereon' and suitable screws to theangnlar-flange 25 of the link 17 Itwill noted, as illuswhen its coils are energized to attract the trated in Fig. 4, that when the'parts are in normal position the lower end of the link 19 is in actual contact with the end of the spool magnet 27, and this link is preferably formed of soft iron, so that it constitutes the armature of the magnet. Therefore when the circuit through the magnet is closed the link 19 is held against separating from the link 17 and when the lever 15 is depressed motion will be imparted to the 7 rod 14. Due to the fact that the link 19 in normal position lies in actual engagement with the core'of the spool magnet, there is no air gap to be overcome by the magnet link thereto, and the magnet may accord- 'ingly bemade materially smaller.

The lever 15 is held in normal position by a coiled spring 28, one end of which is connected to the lever'about midway of its ends and the other end of which is connected to a brace or support 29 which constitutes a continuation of'the angularly extending arm 30 secured at its lower end to one of the compression bolts or tie rods 31 of the frame. In order to hold the support 29 in substantially vertical or upright position, a second bracing member 32 is securedat one end to the 31111530 and at the other endto the front tie rod 33.

inthe form of a push button 35 mounted on an arm 36 secured on the opposite side of the frame in substantially the same manner as is the support 29. The circuit connections of the coils of the magnet are more fully illustrated in Fig. 8. In this figure it will be noted that one terminal of the coils of the magnet is connected by aiconductor 37 with" one terminal of the push-button-35.

The opposite terminal of the push-button is connected by the conductor 38 with one terminal of electricbatt'ery 39. The opposite terminal .of the battery is connected byconductor 40 with the opposite terminal of the coils bfth'e magnet. In place] of an electric battery I'may connect the conductors 40 and 38 directly with the electric lighting supply by means. of a suitable plug 41,'illustrated in dotted linesin Fig. 8. It will be noted that the push-button 35 is so positioned that the operator cannot depress the opera-tlng lever 15 and at the same time operate the push button 35 by the same hand.

hand first closes the circuit through the magnet 27 by operating the push 7 button 35 .keeping the circuit through the magnet27 closed with one hand, with the other band 125'- he depresses the lever 15, and, due to the fact that the link 19 is held by the magnet 27 and the two links 19 and. 17 cannot-therefore separate, the movement imparted to the The circuit through the coil of the magnet 27 is controlled by a circuit controller In tripping a press the operatorwith one" lever 15. will be transmitted to the rod 14 and the tripping mechanism operated. If at any time before the press is actually tripped the operator removes either hand, the tripping mechanism will fly back to normal poand the links 17 and 19 permitted to separate, thereby disconnecting the operating lever 15 from the rod Hand permitting the tripping mechanism to fly back to normal position. If he removes his hand from the operating lever 15 the lever will fly back to normal position under the influence of the spring 28, and with it the tripping mech anism. 1t is therefore seen that until the press is actually tripped both hands of the operator must be used.

\Vhile I have shown and described one embodiment of my invention, it will be understood that various ,modifications or changes may be made therein without departing from the spirit of my invention as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: i

1. The combination with a tripping mechanism, of a movable member for actuating said mechanism, nor1 nally inoperative means for effecting an actuating connection between said movable member and said trippin mechanism, electromagnetic meansfor ren ring said connection effecting means operative, and a circuit controller for saidelectromagnetic means, said circuit controller being placed apart from said movable member, for the purposes set forth.

2'. The combination with a tripping mechanism, of an operating member therefor, connecting means for connecting the member and tripping mechanism including an electromagnet, said connecting means being normally in operative position but inope'ra-; tive to connect the lever and mechanism unless the circuit through the magnet is closed, and a circuit controller for said mag- ,net, said circuit controller and said operat ing member being placed apart, for the pur-' poses set forth. L I

3. The combination with a tripping mechanism, of a member for operating the same, connecting means between said member and tripping mechanism including an electromagnet said connecting means being .arranged to become inoperative upon the open, ing of the circuit through the magnet, and a circuit controller for saidfmagnet, said controller and said member being placed apart, for the purposes set forth 4. The combination with a tripping mechanism, of a member foroperatingthe same,"

electromagnetically' controlled means for" connecting the; member and tripping mec h-.

the circuit through said magnet, said controller being placed apart from said memher, and means for returning the tripping mechanism to non-tripping position in eventeither the lever or the circuit controller is released before the tripping mechanism operates, forthe purposes set forth. p

5. ,The combination with a tripping mechanism, of a member for operating the same, means tending to return saidv member to normal position, electromagnetically .controlled connecting means between the lever, and tripping mechanism arranged to disconnect the lever and tripping mechanism in event the circuit through such electromagnetic means is opened, and means, posi tioned apart from said member, for controlling said, electromagnetic connecting means, forthe purposes set forth.

6. The combination with a tripping mechanism, of a member for operating the same, a pair of connect-ing links pivoted together at one end, one of said links being connected to said member andth'e other of said linksbeingconnected to the tripping mechanism, and said links being arranged so as to tend to-separateiwhen the lever is depressed, and

an electromagnet .for preventing. the separation of said links, p

'7. The combination'with .a tripping mechanism, ofa member for operating the same, a link pivotally connectedto said member and having its opposite end freely movable, a second link pivoted "to the free end of said link-and connected at its opposite end to the tripping mechanism, electromagnetic means for fixing the free end of the link relatively 'tothe tripping mechanism, and a circuit controller for said means, said controller being placed apart from said member, for the pu'rposesset forth.

The combination with a tripping mechanism, of a member for operating the same,

apairof connecting links pivoted together "at one end, one of said links being connected to the tripping mechanism and the other of said links'being connected to said ,member,

said links. having a tendency to separate when the lever is depressed, an electromagnet "mounted on neof saidlinks and having its core arranged when the links are 'in normal position to engage the other link' whereby'when the circuit through the coils ofthe magnet is closed the links will be.

prevented from separating, and acircuit controller for said magnet said circuit con-; troller being placed apartfrom .said mem-' her, for the purposes set forth.

-9. The combination with a tripping mechanism, of, an operatin'g member therefor, connecting means-between said member and said tripping mechanism, said connecting means being normally inoperative but in operative position, "an electromagnet adapted;

anism, a' circuit controller for contro ing when energized,

render. sa d connecting means operative, and a circuitcontroller for said electromagnet, placed apart from said operating member, for the purposes set forth. 1

10. The combination With a trip mechanism, of a member for operating the same and normally inoperatively' connected to the trip mechanism, electromagnetic means for connecting the said member and trip mechanismin operative relation, and acircuit controller for said electromagnetic means,

I said controller-being placed apart from said perating member,

for the purposes set forth.

In Witness whereof, Ihave hereunto sub- 1 scribed my name in the presence of tWo witnesses.

REUBEN B. BENJAMIN.

Witnesses: i

y W. PERRY HAHN,

MABEL REYNOLDS. 

